Myers A C, Undem B J, Weinreich D
Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201.
Am J Physiol. 1990 Dec;259(6 Pt 1):L403-9. doi: 10.1152/ajplung.1990.259.6.L403.
Active and passive membrane membrane properties of parasympathetic neurons were examined in vitro in a newly localized ganglion on the right bronchus of the guinea pig. Neurons could be classified as "tonic" or "phasic" based on their action potential discharge response to suprathreshold depolarizing constant current steps. Tonic neurons (39%) responded with repetitive action potentials sustained throughout the current step, whereas phasic neurons (61%) responded with an initial burst of action potentials at the onset of the step but then accommodated. Tonic and phasic neurons could not be differentiated by other active or passive membrane properties. Electrical stimulation of the vagus nerve elicited one to three temporally distinct fast nicotinic excitatory potentials, and tetanic stimulation of the vagus nerve evoked slow depolarizing (10% of neurons) and hyperpolarizing (25% of neurons) potentials; the latter was mimicked by muscarinic receptor activation. Similar slow and fast postsynaptic potentials were observed in both tonic and phasic neurons. We suggest neurons within the bronchial ganglion possess membrane and synaptic properties capable of integrating presynaptic stimuli.
在豚鼠右支气管上新定位的神经节中，对副交感神经元的主动和被动膜特性进行了体外研究。根据神经元对阈上去极化恒定电流阶跃的动作电位发放反应，可将其分为“紧张性”或“相位性”。紧张性神经元（39%）在整个电流阶跃期间以持续的重复动作电位做出反应，而相位性神经元（61%）在阶跃开始时以初始动作电位爆发做出反应，但随后出现适应性变化。紧张性和相位性神经元不能通过其他主动或被动膜特性进行区分。迷走神经的电刺激引发一到三个时间上不同的快速烟碱样兴奋性电位，迷走神经的强直刺激诱发缓慢去极化（10%的神经元）和超极化（25%的神经元）电位；后者可被毒蕈碱受体激活模拟。在紧张性和相位性神经元中均观察到类似的慢和快突触后电位。我们认为支气管神经节内的神经元具有能够整合突触前刺激的膜和突触特性。
